Union Instability as an Engine of Fertility? A Micro-simulation Model for France

Micro-level relationships between union formation or dissolution and childbearing haveimplications for fertility that have not been thoroughly examined. In this paper, we suggestthat these relationships comprise an ‘engine’ that produces variation and change aroundreplacement level fertility. On the one hand, union dissolution reduces opportunities forconceiving and bearing children. At the same time, it produces a pool of persons who mayenter new partnerships and produce ‘extra’ children. The balance between these twoopposing forces and their implications for fertility levels is unknown and will depend inpart on the timing of union formation and parenthood. In this paper, we estimate theparameters of these micro-level relationships for female respondents to the 1999 French`Etude de l’Histoire Familiale´. We use those parameters to simulate the implications ofnon-union childbearing, union dissolution and re-partnering for completed family size. Wealso investigate the extent to which links between union formation or dissolution andchildbearing depend on the timing of unions and births